1. Field of the Invention
The present invention relates to a folding device, and more particularly to a folding device for a scooter.
2. Description of Related Art
Normally, a scooter has a foldable handle, such that not much space is needed when the scooter is put away for storage. A conventional scooter usually includes a head tube, a base pivotally connected to the head tube, a front wheel assembly rotatably connected to the head tube and another wheel assembly rotatably mounted on the opposite end of the base. The pivotal connection between the base and the head tube is achieved by a combination of a bolt and nut whereby the bolt is inserted through both the base and the head tube, and the nut tightens and holds the head tube in position. With such an arrangement, at least two separated through holes are defined in the base. One hole is defined to hold the handlebar in an upright position relative to the base, and the other hole is defined to secure the handlebar in a horizontal or stowed position relative to the base. This type of scooter needs an extra tool(s) to open or fold the scooter, which makes the scooter inconvenient to the user.
Still, there is another type of conventional connection between the base and the head tube. This connection is achieved by a bolt and spring combination. With the bolt and spring combination, the user is readily able to change the relative position between the handlebar and the base. Although, the scooter has a convenient connection structure between the base and the handlebar, the connection is not as secured as it should to be. When the scooter of this type is in use, the handlebar will shake and make the user standing on the base very unstable and unsafe.
With reference to FIG. 7, a conventional folding device for a scooter has a connector (3). a stud (6), a limit (51) and a spring (S). The connector (3) is securely connected to the base (A) and pivotally connected to a heat tube (5). The stud (6) is inserted through the connector (3) and the head tube (5) to enable the head tube (5) to pivot relative to the connector (3). The limit (51) is movably received in an arcuate opening (31) in the connector (3), The spring (S) is connected between the limit (51) and the stud (6). Furthermore, a notch (32) defined at each distal end of the arcuate opening (31) communicates with the arcuate opening (31), and the limit (51) is alternatively received in either one of the notches (32).
When the limit (51) is received in forward the notch (32), the head tube (5) stands in an upright position relative to the base (A), and when the limit (51) is received in the aft notch (32), the head tube (5) lies parallel to the base (A). When the limit (51) is moved between the two notches (32), the spring (S) applies a downward force to the limit (51), such that the limit (51) is pulled into and held in the notches (32). This secures the relative position between the heat tube (5) and the base (A). This kind of folding device does have the capability to fold and open the scooter. However there are still shortcomings that need to be overcome.
The friction between the limit (51) and the arcuate opening (31) when moving the limit (51) between notches (32) will enlarge the dimension of the arcuate opening (31) and damage the surface of the limit (51), which will cause the downward force from the spring (S) to be diminished. A sudden impact to the base (A) could cause the limit (51) to jump out of the notch (32) and the scooter to unexpectedly fold, which could be extremely dangerous especially at moderate to high speeds.
To overcome the shortcomings, the present invention provides a scooter with an improved folding device that allows the engagement between the head tube and the base to be secured when in use.